The compound of Formula I:
has been found to be an effective inhibitor of Lymphocyte Function-Associated Antigen-1 (LFA-1) interactions with the family of Intercellular Adhesion Molecules (ICAM), and has desirable pharmacokinetic properties, including rapid systemic clearance. Improved forms, including crystalline forms, and their uses in treatment of disorders mediated by the interaction of LFA-1 and ICAM are described herein. Novel polymorphs of the compound of Formula I which may afford improved purity, stability, bioavailability and other like characteristics for use in pharmaceutical formulations and methods of use thereof are useful in treating disease.